Improvement in gearing for lathes



UNITED STATES PATENT OFFICE.

WALTER: FITZGERALD, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT INGEARING FOR LATHES, 80C.

Specication forming part of Letters Patent No. 511,519, dated May 8, 1866.

To all whom t may concern:

Be it known that I, WALTER FITZGERALD, of Boston, in the county of Suifolk and State of Massachusetts, have invented an Improved Driving and Reversing Gearing for Lathes, Ste.; and I do hereby declare that the following, taken in connection with the drawings which accompany and form part of this speciiication, is a description of my invention sufficient to enable those skilled in the art to prac* tice it.

It is well known to practical mechanicians that the rotation of the spindle in lathehad stocks and some other machinists tools is required to he in opposite directions, and also that the reverse or backward rotation is generally required to be at a greater rate of speed than the forward rotation, the backward rotation being generally for the purpose of returning the operating-tool to its starting-place.

The apparatus usually employed for the purpose of giving said reverse rotations and at different rates of speed is commonly known by the general term of overhead reversinggear,7 which embraces two belts, one openl and the other crossed, anddriving two loose pulleys on a shaft, which has thereon the cone or other pulley which drives the machine beneath, and

a plain or a conical clutch arranged so that it must turn with the shaft but can be slid in either direction to engage with either of the loose pulleys.

By my invention I dispense with one of the belts, thereby saving the cost of it and its two pulleys, and by substitution of a simple arrangement in lieu of the clutch-coupling be- -fore named I accomplish in a better and g, and the stud c having thereon the spur-wheel h and pulley t'.

To the hanger c is pivoted the shipper-lever j, this having in the upper end thereof a camshaped slot, which embraces a pin, 7c, fixed in the rocker c, the function of the cam-slot being to shift the rocking-piece c, and to hold it in position when shifted.

The shaft Zruns in bearings in the hangers c and b, and has fixed thereon the cone-pulley m, over which the belt runs which drives the lathe or other machine below', and on said shaft is fixed the spur-wheel a.

The spur-wheels a, h, and f are of uniform size; but the spur-wheel g is larger than the others, andwill, when the. shipper is in the position seen in Fig. l, be meshed intothe wheel n, in which condition of things the rotation of shai'tl will be in the same direction with the rotation of the pulley t', but will rotate at greater speed than does the pulley t', as will be readily seen.

When the shipper j is in the reverse position to that shown in Fig. 1, then the wheels n and g will be out of contact, but the wheels u and It will be m'eshed together, and :as these are of uniform size, and have no intermediates be tween them, it will be' obvious that the shaft Zwill be turned in the direction opposite to that in which the pulleyt' is moving, and that the pulleyt' and shaftl will make the same number of turns per minute.

Having described the old construction, on which my invention is an improvement, and the detail of combination and arrangement of my invention, it will now be understood that my invention consists in combining with the hangers, shaft, and pulley thereon of an overhead gearing the rocking piece c, with thcstuds, spur-wheels, and pulley thereon, the cam-slotted shipperj, and the spur-wheel n.

I claim- The overhead driving and reversing gearing,

constructed and operating substantially as described.

WALTER FITZGERALD, Witnesses:

J. B. CROSBY, F. GOULD. 

